Apparatus for cutting a wire and crimping a winding to the wire

ABSTRACT

This is an apparatus for cutting a wire and crimping a winding to the cut wire. A drive shaft is coupled to means for feeding wire to be cut and rotating means for cutting the wire and crimping the winding to the wire. The rotating cutting means includes a disk cutter having a bevelled edge. During the course of one revolution of the cutter, the outermost portion of the bevelled edge is positioned adjacent the point where the wire is to be cut, and the plane of the bevelled edge is slightly less than parallel with the axis of the wire so as to cause a crimping to the wire of the winding which surrounds the wire while the wire is being cut.

United States Patent [191 Marks [54] APPARATUS FOR CUTTINGA WIRE AND CRIMPING A WINDING TO THE WIRE [75] Inventor: John L. Marks, Peabody, Mass.

[73] Assignee: International Telephone and Telegraph Corporation, Nutley, NJ.

[22] Filed: May 26, 1971 [2]] Appl. No.: 147,096

[52] US. Cl. ..29/203 D, 29/203 R [51] Int. Cl. ..H0lr 43/00 [58] Field of Search ..29/203 D, 203 DT, 203 R,

56 References Cited UNITED STATES PATENTS 2,720,475 10/1955 Geiger ..29/203C 51 Feb. 27, 1973 Primary ExaminerThomas l-l. Eager Att0meyC. Cornell Remsen, .lr., Walter J. Baum, Paul W. Hemminger, Charles L. Johnson, Jr., Philip M. Bolton, Isidore Togut, Edward Goldberg and Menotti J. Lombardi, Jr.

[5 7] ABSTRACT This is an apparatus for cutting a wire and crimping a winding to the cut wire. A drive shaft is coupled to means for feeding wire to be cut and rotating means for cutting the wire and crimping the winding to the wire. The rotating cutting means includes a disk cutter having a bevelled edge. During the course of one revolution of the cutter, the outermost portion of the bevelled edge is positioned adjacent the point where the wire is to be cut, and the plane of the bevelled edge is slightly less than parallel with the axis of the wire so as to cause a crimping to the wire of the winding which surrounds the wire while the wire is being cut.

10 Claims, 6 Drawing Figures PATENTEBFEBZY ma WEIE a.

INVENTOR JOHN L. MARKS ATTORNEY APPARATUS FOR CUTTING A WIRE AND CRIMPING A WINDING TO THE WIRE CROSS REFERENCE TORELATED APPLICATIONS This invention is related to copending U.S. application J. L. Marks 2, Ser. No. 147,097, filed May 26, 1971, said application being assigned to the assignee of the instant application.

BACKGROUND OF THE INVENTION This invention relates to an apparatus fur cutting a wire and crimping a winding to the cut wire, and more particularly, for cutting and crimping a filament to be used in a lamp.

Electrode wires of the type used in fluorescent lamps are generally made in a well-known standard fashion, by wrapping a winding around a tungsten wire and a molybdenum wire wherein this combination is wrapped around a molybdenum mandrel. After suitable strain annealing in a protective atmosphere at temperatures of approximately 1,350 to l,600 C., the assembly is cut to predetermined lengths which generally are of the order of 17 mm. After cutting, the molybdenum mandrel and wire are removed leaving the basic tungsten wire and winding. Generally, during cutting, however, the winding has a tendency to extend beyond the tungsten wire in an overwind or basket wire fashion thus causing considerable difficulty and entanglement in subsequent stages of the manufacture of the electrodes and lamp when using automatic equipment.

SUMMARY OF THE INVENTION It is therefore an object of this invention to provide an apparatus for preventing the winding from extending beyond the cut wire.

It is a further object of this invention to provide an apparatus for effectively cutting a wire and crimping a winding thereto in an efficient manner.

According to a broad aspect of this invention, there is provided an apparatus for cutting a wire and crimping a winding to said cut wire comprising rotational drive means including a drive shaft, means coupled to said drive shaft for feeding wire to be cut, and rotating means coupled to said drive shaft for cutting said wire and crimping said winding to said wire.

A feature of this invention provides that said rotating cutting means includes a cutter wherein during the course of one revolution of said cutter, the outermost portion of a first bevelled edge on said cutter is positioned adjacent that point where the wire is to be cut, the plane of said first beveled edge being at an angle of approximately 2 to 4 with the axis of the wire being fed was to cause a crimping of the winding to the cut wire.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a wire assembly;

FIG. 2 shows the wire assembly wrapped around a mandrel;

FIG. 3 is a top view of the wire cutting apparatus;

FIG. 4 is a sectional view of the cutting apparatus taken along plane XX shown in FIG. 3;

FIG. 5 is atop view of the disk cutter; and

FIG. 6 is a cutaway portion of an edge of the cutter blade.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The wire cutting apparatus described in this'embodiment is used to manufacture cathodes, more particularly heater coils for use in fluorescent lamps but, of course, is not confined to the manufacture of these products and can be used to cut short wires of accurate length where it is necessary to crimp a winding to the cut wire.

FIG. 1 shows tungsten winding I wrapped at a predetermined uniform pitch around the parallel combination of tungsten wire 2 and thicker wire 3 which can be a suitable metal such as molybdenum. This assembly as shown in FIG. 2 is now wrapped around a mandrel 4, wherein mandrel 4 consists of a suitable material such as molybdenum. The final assembly, which has an overall thickness of 0.030 inches, is fabricated as part of a continuous process well known in the art. After the assembly, as: shown in FIG. 4, is constructed, it is subjected to a deforming process which generally consists of strain. annealing in a controlled hydrogen atmosphere at temperatures ranging from l.350 to l,600 C. This continuous wire assembly is then reduced to short uniform lengths using our wire cutting apparatus, after which cutting operation the molybdenum mandrel 4 and molybdenum wire 3 are removed, usually by etching in an acid.

The top view of the wire cutting machine is shown in FIG. 3, wherein a suitable constant speed motor 5 drives shaft 6. Pulleys 7 and 8 coupled together by belt 9 are used to rotate the drive shaft 10 at a reduced rotational speed with respect to shaft 6, the speed reduction being provided by suitably selected pulleys. In this example, motor 5 rotates shaft 6 at 3,700 rpm and the pulley arrangement rotates drive shaft 10 at 1,500 rpm. Drive shaft 10 is directly connected to a gear train assembly 11 and specifically to input gear 12. An output gear 13 is then used to drive shaft 14 at a reduced rotational speed with respect to drive shaft 10, which reduced speed is determined by the final gear reduction ratio of gear train 11. This gear train, of course, is a standard purchasable item or it can be assembled by using appropriate size gears, the size of the gears being determined by the gear reduction ratio desired. Shaft 14 is attached to a drum is by the use of suitable set screws in portion 16 of drum 15.. In this example, the drum is made of standard machine steel. Drum 15 engages the wire assembly W which consists of mandrel 4, wires 2 and 3 in winding 1, and directs the assembly through a hole 17 in a die 18, which die rests within a support 19. The wire assembly W exits the opposite end of hole 17 in a continuously fed fashion where it is cut by the cutter assembly. At this point, it should be noted that while the wire feed is a continuous feed, non-continuous feed systems could be used in place thereof. Thus, in this example, the continuous feed means consists of the gear train 11 which is connected to drive shaft 10, drum 15 which is connected to the output of the gear train via shaft 14, and the support 19 which holds die 18. The wire assembly is cut at the rate of the rotational speed of shaft 10, which shaft is attached via suitable set screws to cutter holder 20. Cutter holder 20 has a cylindrical shape and a flat surface portion 21 which extends outward in a flange-like manner. Cutter blade 22 in this example is a disk-shaped cutter and is attached to the flat surface portion 21 of cutter holder 20 using a suitable fastening arrangement.

A sectional view of FIG. 3 along plane XX is shown in FIG. 4, wherein the cutter is in the rotational position to begin to cut wire assembly W. The wire assembly is fed to drum via a suitable standard spool feed. Rubber rollers 23 and 24 are shown pressing the wire assembly against drum 15 so as to enable drum 15 to feed the wire assembly W through hole 17 in support die or jacket 18. Rollers 23 and 24 were not shown in FIG. 3 for purposes of clarity. Support jacket or die 18 is made of steel in this example and is approximately 1- "Vs inches long and approximately 0.312 inches in diameter. Jacket 18 has a die 25 placed therein to narrow the feed hole for the wire assembly to approximately 0.075 inches in diameter, and provide support and a cutting edge for the wire as it engages cutter 1 blade 22. Die 25 and cutter blade 22 in this example are both made of a tungsten-carbon alloy, known in the trade as Grade 558 Carboloy. It should be noted that while the adjacent edge 26 of die 25 is perpendicular to the axis of hole 17 for an approximate distance of 1/64 inches from hole 17, thereafter the remainder 27 of that surface tapers from the plane of edge 26 at approximately 215 in the direction away from cutter blade 22 so as to provide some clearance for the floating cutter blade.

Cutter blade 22 as shown in FIG. 5 in this example has a disk shape with an outside diameter of approximately 1-7/16 inches and a thickness of approximately 0.067 inches. A cutaway portion of blade 22 is shown in FIG. 6. Blade 22 has a first bevelled edge 28 which edge 28 makes an angle G of approximately 52 to 54 with the plane perpendicular to that of the disk. Cutter blade 22 also has a second bevelled edge 29 which makes an angle F of approximately 33 with the plane of the cutter disk. Also, in this example, the second bevelled edge 29 extends a vertical distance 1-! equal to 1/32 inches from the outermost portion 30 of cutter blade 22. The second bevelled edge 29 serves to provide clearance for cutter 22 as it rotates past die 25.

As shown in FIG. 4, when the outermost portion 30 of cutter blade 22 contacts and begins to cut the wire assembly W, the first bevelled edge 28 is almost parallel to the wire at point A and varies from the horizontal axis of hole 17 by approximately 2 to 4 so that the wire is cut between point A and point B, point B being the bottom portion of the exit hole, so that the wire is severed therebetween. Not only does such an arrangement provide a satisfactory cutting of the wire but the near parallel bevelled edge 28 provides a crushing action so that winding 1 is crimped to tungsten wire 2 therefore eliminating any possibility of the winding peeling off or extending beyond the end of the tungsten wire 2. Furthermore, when cutter blade 22 contacts point A of the wire, the plane of the disk of the cutter blade 22 and the plane of the flat surface 21 of cutter holder makes an angle of approximately 40 with the horizontal axis of hole 17. This angle can be adjusted to provide maximum cutting force for the cutter while also providing sufficient clearance for the continuously fed wire so that no portion of the rotating cutter blade comes in contact with the wire assembly until the cutter is in position to actually cut the wire. The length of the cut wire actually is determined by the formula where L length of wire in millimeters; D diameter of the drum in inches;

R the gear train ratio; and

K is the conversion factor equal to 25.4 for converting inches to millimeters.

In this example, with R equalling 10 and D equalling 2.19 inches, the length of wire to be cut equals 17 mm. From the above formula, it can be seen that by varying the diameter of the drum 15 or the reduction ratio of the gear train 11, the length of the cut wire could be varied. However, the largest length of wire which can be cut is limited since there is a point beyond which the continuously fed wire will prematurely interfere with some portion of the rotating cutter blade 22, and when the angle of the surface portion 21 of holder 20 and the disk plane 31 of cutter blade 22 is with respect to the horizontal axis of hole 17, the maximum length of wire that could be cut is approximately 19 mm. Generally speaking, when the angle formed between plane 31 and the horizontal axis of hole 17 is reduced, the maximum length of cut wire is extended. However, in this example, it has been found that by reducing the disk plane angle to a value less than 40, the effectiveness of the crimping action is reduced. However, if longer cut wire sections are required, additional clearance could be found by removing portions of cutter blade 22.

In this example, cutter holder 20 is approximately 1% inches in diameter and has a 54 inches hole therein so as to fit around and grasp shaft 10. Actually, cutter blade 22 should be so mounted on cutter holder 20 that the outermost portion 30 of the cutter blade will engage the wire assembly at point A just as the wire assembly leaves hole 17 so that the cutter blade will clear the die and still cleanly cut the wire assembly W. In this example, the axis of the cutter holder is horizontally aligned with the axis of the wire to be cut. This axis is approximately 1% inches from point A where the wire will be cut, and the cutter blade 22 is so positioned on the cutter holder 20 to accomplish this purpose. It should also be noted that except for extended portion 32 of cutter holder 20, the remaining portions of holder 20 are not in line with and will not interfere with the continuously fed wire. It should further be noted that the extended portion 32 of cutter holder 20 serves the purpose of providing balanced mechanical support for cutter blade 22.

It is to be understood that the foregoing description of specific examples of this invention is made by way of example only and is not to be considered as a limitation on its scope.

I claim:

1. An apparatus for cutting a wire and crimping a winding to said cut wire comprising:

rotational drive means including a drive shaft, a first shaft, first means coupled to and driving said first shaft, and a pulley arrangement for coupling said first shaft to said drive shaft;

means coupled to said drive shaft for feeding wire to be cut; and

rotating means coupled to said drive shaft for cutting said wire and crimping said winding to said wire.

2. An apparatus according to claim 1 wherein said first means comprises a motor.

3. An apparatus according to claim 1, wherein said feed means includes a support having a hole therein for guiding the feed wire, whereby the wire is cut as it leaves the hole.

5. An apparatus according to claim 3, wherein said rotating cutting and crimping means includes:

a cutter holder attached to said drive shaft; and

a cutter blade attached to said cutter holder.

6. An apparatus according to claim 5, wherein said cutter holder has a cylindrical shape and a flat surface portion, and said cutter blade is mounted on said flat surface portion.

7. An apparatus according to claim 5, wherein said cutter blade is a disk having a first and second surface, said disk having a first bevelled edge extending to said first surface.

8. An apparatus according to claim 7, wherein said disk has second bevelled edge extending to said second surface.

9. An apparatus according to claim 7, wherein during the course of one revolution of said cutter, the outermost portion of said first bevelled edge is positioned adjacent the hole in said support to engage and cut said wire as it leaves the hole, the plane of said first bevelled edge being at an angle of approximately 2 to 4 with the axis of the hole in said support so as to cause a crimping of the winding to the cut wire.

10. An apparatus according to claim 9, wherein the plane of said disk is at an angle of approximately 40 with the axis of the hole in said support when the outermost portion of said first bevelled edge is positioned adjacent the hole in said support.

* l I i 

1. An apparatus for cutting a wire and crimping a winding to said cut wire comprising: rotational drive means including a drive shaft, a first shaft, first means coupled to and driving said first shaft, and a pulley arrangement for coupling said first shaft to said drive shaft; means coupled to said drive shaft for feeding wire to be cut; and rotating means coupled to said drive shaft for cutting said wire and crimping said winding to said wire.
 2. An apparatus according to claim 1 wherein said first means comprises a motor.
 3. An apparatus according to claim 1, wherein said feed means includes a support having a hole therein for guiding the feed wire, whereby the wire is cut as it leaves the hole.
 4. An apparatus according to claim 3, wherein said wire is continuously fed and said feed means further includes: a gear train having an input and output, the input of said gear train being coupled to said drive shaft; a rotating drum for engaging the wire to be cut and for propelling the wire through the hole in said support, said drum being coupled to the output of said gear train; and first and second rollers for pressing said wire against said rotating drum.
 5. An apparatus according to claim 3, wherein said rotating cutting and crimping means includes: a cutter holder attached to said drive shaft; and a cutter blade attached to said cutter holder.
 6. An apparatus according to claim 5, wherein said cutter holder has a cylindrical shape and a flat surface portion, and said cutter blade is mounted on said flat surface portion.
 7. An apparatus according to claim 5, wherein said cutter blade is a disk having a first and second surface, said disk having a first bevelled edge extending to said first surface.
 8. An apparatus according to claim 7, wherein said disk has second bevelled edge extending to said second surface.
 9. An apparatus according to clAim 7, wherein during the course of one revolution of said cutter, the outermost portion of said first bevelled edge is positioned adjacent the hole in said support to engage and cut said wire as it leaves the hole, the plane of said first bevelled edge being at an angle of approximately 2* to 4* with the axis of the hole in said support so as to cause a crimping of the winding to the cut wire.
 10. An apparatus according to claim 9, wherein the plane of said disk is at an angle of approximately 40* with the axis of the hole in said support when the outermost portion of said first bevelled edge is positioned adjacent the hole in said support. 